The present invention relates to an improved mounting bracket for poster display devices or any other structure having coil spring mounts.
Poster display devices of the general type to which the present invention particularly relates, comprise a frame having a relatively large surface area mounted to a spring structure which permits the frame to deflect downward upon the application of a force thereto, such as, for example, the wind when the device is located out-of-doors. Such devices are shown, for example, in U.S. Pat. Nos. 3,646,696 and 3,662,482. Known devices of this type have utilized various methods of mounting the coil spring to the frame and the base of the display device.
For example, one such known device utilizes a pair of threaded "J"-shaped bolts that are hooked through the coils of the spring and are threadedly secured to the display structure. Although providing a relatively easy means of assembly, the "J" bolts often tend to become weak at the joint and might break after prolonged use of the poster display structure.
Another known alternative is a screw-type mount having a shaft diameter equivalent to the inside diameter of the coil spring. The shaft of the screw is threaded to mate with the coils of the spring so that the coil spring is secured to the structure by screwing the mount into the spring. The primary disadvantage of this method is that, in order to properly secure the coil springs to the frame, too many coils must be deadened. This is particularly apparent when the screw-type mount is also employed to fasten the coil springs to the base of the device. With a sufficient number of dead coils, the frame might not deflect as well as it should. In addition, this type of mounting device requires a different sized screw mount for each coil spring of a different diameter.
Another widely used method of securing coil springs to a structure is by welding. However, welding tends to weaken the springs which results in the display sign not completely returning to its upright position once deflected. Also, if welded, the display device cannot be shipped disassembled, which can be an inconvenience. Furthermore, since a weld is a permanent-type bond, a part of the display device cannot be as readily replaced in the event only a part of the structure is damaged.
The present invention seeks to alleviate the problems associated with known coil spring mounting devices by providing a mounting device that is readily installed and provides easy assembly of the display or other structure without adversely affecting the intended operation of the coil springs. In particular, the mounting bracket according to the present invention, preferably comprises a metal plate having at least two different levels. A hole is formed through each level of the bracket proximate the ends of the plate and the holes are threaded. The bracket is adapted to fit between adjacent coils of the spring so that the holes are parallel to the axis of the spring. The different levels are provided to compensate for the inclination in the coils of the spring between the ends of the bracket. A pair of mounting bolts are then fitted through corresponding holes or slots in the display structure and secured to the brackets. Since the holes in the bracket are parallel to the axis of the coil spring, the bolts inserted through the holes in the structure are easily aligned with the holes in the bracket, thus facilitating assembly.
Thus, the present invention provides a mounting bracket which can readily be secured to various sized springs without weakening the springs nor deadening a significant number of coils. In addition, the mounting bracket will remain secured to the coil spring regardless of the number of times the frame of the structure is deflected.